Photo: Wikipedia, CCEverything's Better with Fricking Lasers!The internal combustion engine (ICE) has served humanity well in many ways, but it is also causing many problems. One of the big challenges that we're faced with is to greatly reduce the numbers of CO2-spewing ICEs by replacing them with better alternatives (biking, mass transit, electrified vehicles powered by clean energy, etc), and making sure that those that remain are as clean and efficient as possible. One way to just that might involve replacing the venerable 150-year old spark plug with... lasers!Photo: chuckoutrearseats, Flickr, CC

Progress in laser technology has created lasers that are small, rugged, and cheap enough to be fitted into combustion engines. This offers the potential of better controlled fuel combustion, and leaner fuel-air mixes, leading to fewer NOx emissions and better fuel economy.

Spark plugs can ignite leaner fuel mixtures, but only by increasing spark energy. Unfortunately, these high voltages erode spark plug electrodes so fast, the solution is not economical. By contrast, lasers, which ignite the air-fuel mixture with concentrated optical energy, have no electrodes and are not affected.

Lasers also improve efficiency. Conventional spark plugs sit on top of the cylinder and only ignite the air-fuel mixture close to them. The relatively cold metal of nearby electrodes and cylinder walls absorbs heat from the explosion, quenching the flame front just as it starts to expand.

Lasers can focus their beams directly into the center of the mixture. Without quenching, the flame front expands more symmetrically and up to three times faster than those produced by spark plugs.

The laser was built from "two yttrium-aluminum-gallium (YAG) segments, one doped with neodymium, the other with chromium." The resulting device is only 9 millimeters in diameter and 11 millimeters long!

A cool looking laser, but not actually the kind that would be used in spark-plugs. Photo: Public domain.If you like this article, you can follow me on Twitter (@Michael_GR) and Stumbleupon (THMike). Thanks.